Individuazione e applicazione di composti volatili repellenti per il controllo delle popolazioni del punteruolo rosso delle palme

Abstract

The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier (Coleoptera, Curculionidae), is one of the most severe pests of ornamental palm species in urban areas of Mediterranean countries. The cryptic nature of the weevil, and the gaps in our knowledge of its biology and ecology, hamper the development of efficient and sustainable strategies to limit its diffusion. Control strategies based on semiochemicals can be considered a suitable alternative for RPW population management, particularly in urban areas. Nevertheless these strategies might be improved by broadening our knowledge of behavior modifying stimuli suitable for adult manipulation, such as repellent chemical compounds. A first study about the possibility to use repellent compounds for the control of Rhynchophorus species was carried out in Central America using -pinene and other undisclosed compounds. More recently, in Italy, in laboratory and field experiments were tested seventeen non-host volatiles as possible repellents against the RPW, selected for their repellent skills towards other arthropods. These studies showed promising results in term of repellency elicited from a-pinene, methyl salycilate, 1-octen-3-ol and geraniol that elicited: 1) Significant disruption of pheromone trap attraction; 2) reduction of female’s egg deposition activity; 3) antifeedant properties. The possibilities to use candidate repellent compounds in a “Push and Pull” or “stimulo-deterrent diversionary” strategies are discussed.